Egyptian police have been clearing two protestcamps loyal to deposed president Mohamed Morsi,with reports 250 people were killed by securityforces.

The sound of gunfire rang out as police, backed byarmoured vehicles and bulldozers, fired tear gas atthe demonstrators who are demanding Mr Morsibe reinstated as the country's leader.

Sky's Sam Kiley at the scene of the Rabaa alAdawiya camp said it was "under very heavygunfire".

He added: "There are machine gun rounds andsnipers on the roof that are preventing people fromgetting any closer to the field hospital."There is a very large fire that I understand isburning tents and other material that was beingused by the group."

However, army troops were not taking part in theoperation which began shortly after 7am local timein the capital Cairo.

The interior ministry, which is in charge of police,warned security forces would deal firmly withprotesters acting "irresponsibly" and said it wouldguarantee safe passage to those who want to leavethe two sites.

The larger is the Rabaa al Adawiya camp describedas a 'mini town', while the other is in Al NahdaSquare outside the main campus of Cairo Universityin Giza.

The interior ministry said security forces have "totalcontrol" over the smaller camp and police havemanaged to remove most of the tents in the square.Meanwhile, at the edge of the sprawling Rabaacamp, Murad Ahmed said: "It is nasty inside, theyare destroying our tents. We can't breath inside andmany people are in hospital."

A journalist at the scene said he could hear thescreams of women as a cloud of white smoke hungover the site in the eastern suburb of Nasr City.

The Muslim Brotherhood that backsousted Islamist president Mr Morsi claimed over250 people had been killed and 5,000 hurt in thecrackdown, which is almost certain to deepenpolitical turmoil in Egypt.

The raids came after international efforts failed tomediate an end to a six-week politicalstandoff between Morsi's supporters and the army-backed government which took power after he wasousted on July 3.

The state news agency claimed two policemen hadbeen killed by gunfire during the operation.Regional television networks showed images ofcollapsed tents and burning tyres at both sites, withambulances on standby at the scene.

They also showed protesters being arrested and ledaway by troops.

A television feed by a pro-Morsi TV station showedthousands of protesters gathered at the centre ofthe Nasr City site, with many covering their faces tofend off the tear gas.

It said most of the protesters at the other camp fledto the nearby Orman botanical gardens and insidethe sprawling university campus.